Modular construction compressed air/gas dryer system with filtration

ABSTRACT

A modular compressed-gas dryer including in series: an inlet module, a precooler/reheater module, an evaporator module, and a sump module. The modules form columns where at least one column has a filtration chamber. Further provided are a gas outlet and gastight seals between modules. The system creates a first and second set of heat transfer passages where refrigerant passes through the second set in a heat exchange relationship in a direction perpendicular to incoming gas passing in the first set. The filtration chamber conducts chilled gas from the first set to a third set of heat transfer passages. The third set extends through the precooler/reheater in heat exchange relationship with the first set. Chilled gas passes in heat exchange relationship in a direction perpendicular to the incoming gas so that the incoming gas chilled in the evaporator exchanges heat with the incoming gas in the precooler/reheater.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This patent application relates to a compressed air/gas dryer system for generating clean, dry air for use in industrial processes. More specifically this patent application relates to a refrigerant compressed air/gas dryer system comprising modular construction and a replaceable filter.

2. Background

The atmospheric air that surrounds us is contaminated with varying concentrations of hydrocarbons, solid particles and water vapor. When compressed to a working pressure of 100 pound-force per square inch gauge (PSIG), the concentration of these contaminants is increased by a factor of eight to one. If these contaminants are not removed prior to entering a process distribution system they will damage air operated equipment, slow down or stop production, corrode the inside of pipes, spoil product, ruin processes, and drive up energy costs.

Moisture is a serious problem in compressed air systems. Since atmospheric air always contains some amount of moisture, measured in terms of relative humidity. Relative humidity is the ratio of moisture in the air compared to the capacity of moisture that volume of air is capable of holding at a specified temperature. When air is compressed, friction causes the actual air temperature to rise, greatly increasing its ability to hold moisture. At 100 PSIG the quantity of moisture commonly held in eight cubic feet of air is reduced in an area ⅛ its original size. The result of compression is hot, wet, dirty air.

A good general rule is that for every twenty degrees Fahrenheit (20° F.) the temperature of air decreases, its ability to hold moisture is reduced by 50%. As air passes through a plant piping system, the ambient conditions cause the compressed air to cool, causing the formation of liquid water. This water, coupled with particulate matter and oil/lubricant carry-over will cause numerous problems. The water will wash away lubricants from tools and machinery, spoil paint applications, rust the general system, and, if exposed to unfavorable ambient temperatures, freeze.

Particulate matter consists of atmospheric particles that are drawn into a plant piping system through the air compressor intake. Some air system components, along with scale build-up in piping, may introduce additional particulate matter. Particulates traveling through the air system will cause pressure drop to increase, valves and orifices to clog, and product to be spoiled. Particulate matter will clog orifices and valves, damage gear driven equipment, increase system pressure drop and contaminate product.

Airborne hydrocarbons, compressor oils and lubricants are harmful to all downstream equipment and processes. Today's high performance compressor lubricants can cause additional problems, and need to be removed before they cause irreversible damage. They will cause valve and gasket materials to fail, and wreak havoc on processing equipment. Residual oils and lubricants will cause valve wear, spoiled product and system contamination.

Therefore, it is essential to treat process air before it can do any damage to a process system. By drying and filtering compressed air, operation efficiency can be maximized, and equipment productivity and longevity can be greatly increased.

Presently, refrigerated compressed air/gas dryer systems utilize some basic components. For example, there is usually a heat exchange unit used to pre-cool air entering the dryer system and to reheat dry air before the air leaves the dryer. Various systems also use an evaporator for circulating refrigerant to promote condensation of water vapor followed by a means to drain-off the resultant condensation. Dryer systems are further equipped with a filter to clean the compressed air/gas before the air/gas enters the dryer system and/or as the air/gas leaves the dryer system. Additionally, some systems utilize a filter as an intermediate stage component; such as after the evaporator and before the reheater. These traditional dryer systems are large and bulky due to the interconnection of the various components comprising the dryer system. To date, there are no dryer systems contained within a single pressurized housing that efficiently allows the passage of compressed air/gas to flow through the system and exit both dry and filtered. Many prior attempts have been made to mitigate the problems associated with drying gas. For example:

U.S. Pat. No. 5,794,453 discloses an apparatus for removing condensate from a gas. The system has a chiller to cool the gas followed by a separator to remove the condensed liquid. The dried gas is then sent through a reheater before exiting the apparatus. While this apparatus dries and reheats the gas, there are significant drawbacks to this design. First, there is no filtration of the gas to remove particulates or to further condense any remaining water vapor in the gas following chilling. Secondly, the device is inefficient as the hot incoming air is cooled only through the chiller, thus requiring more energy to run and a greater amount of refrigerant to cool the gas.

U.S. Pat. No. 6,470,693 describes a gas compressor refrigeration system. The system has a chiller to cool the gas followed by a separator to remove the condensed liquid. The dried gas is then sent through a reheater before exiting the apparatus. A closed-loop refrigerant system which supplies heat to the reheater and is then recharged to cool the gas in the chiller. While this apparatus dries and reheats the gas, there are significant drawbacks to this design. First, there is no filtration of the gas to remove particulates or to further condense any remaining water vapor in the gas following chilling. Secondly, the device is inefficient as the hot incoming air is cooled only through the chiller, thus requiring more energy to run and a greater amount of refrigerant to cool the gas.

U.S. Pat. No. 7,343,755 presents a gas drying system having a recuperator, a moisture separator, and a refrigerated section housed in a single unit. The recuperator has a pair of fluid flow paths in thermal communication such that incoming hot air is cooled by, and in turn warms, cooled air exiting the system. The incoming air is further chilled in the refrigerated section to cause water in the air to condense into liquid water. The liquid water is then separated from the gas in the separator section. While this apparatus dries and reheats the gas, there is no filtration of the gas to remove particulates or to further condense any remaining water vapor in the gas following chilling.

Importantly none of the example provided above, even combined, construct in a single, compact housing, all the necessary elements to dry and clean compressed air/gas, namely to precool incoming gas, to chill the gas to 33° F., to drain off resulting condensation and to coalesce any remaining water molecules, to remove particulates in the gas, to sense the liquid level (of coalesced condensate) and drain off as necessary, and to reheat exiting gas. Further, none of the above examples employ filtration, and more specifically, filtration using a replaceable filter. Additionally, none of the examples are modularly constructed which prevents them from being disassembled for maintenance and repair. These examples must be completely removed and replaced, adding greatly to the size and cost of such systems.

Thus, there is clearly an unmet and long-felt need for a free-standing, cost effective, refrigerated compressed air/gas dryer system that dries and filters compressed air/gas in a single pressurized housing where the housing further comprises a replaceable coalescing filter; eliminating the need for bulky interconnecting means between subcomponents. Ideally, such a refrigerated compressed air/gas dryer system that dries and filters compressed air/gas in a single pressurized housing would be compatible with a variety of existing dryer systems.

It should be understood that there are other conventional components that, when combined with the refrigerant compressed air/gas dryer system of the present disclosure, fully comprise a finished dryer which is ready for use. Such additional conventional components include a condensing unit (refrigerant compressor, condenser that is either air or water cooled, receiver, accumulator, pressure switches), drain solenoids & valves, cabinetry, controls and wiring, etc.

SUMMARY OF THE INVENTION

It is accordingly an object of the present disclosure is to provide a compressed air/gas dryer system which is comprised of an air inlet compartment, a precooler/reheater compartment, and evaporator compartment and a sump compartment housed in a single pressurized housing.

A further object of the present disclosure is to provide a compressed air/gas dryer system which is housed in a single pressurized housing and which further comprises an intermediate stage replaceable coalescing filter.

Still another object of the present disclosure is to provide a compressed air/gas dryer system where there is a unidirectional air/gas flow circuit through the pressurized housing and a unidirectional refrigerant flow circuit within the evaporator compartment.

Yet another object of the present disclosure is to provide a compressed air/gas dryer system which is comprised of an air inlet compartment, a precooler/reheater compartment, and evaporator compartment and a sump compartment housed in a single pressurized housing where each compartment is an independent module which can be sequentially dismantled and reassembled.

A further object of the present disclosure is to provide a means to measure the level of collected liquid water (condensation) and to evacuate condensation from the system.

Another object of the present disclosure is to provide a compressed air/gas dryer system which has ‘layered’ horizontal compartments, when assembled, comprise vertical column chambers for adding filters.

The above and other objects are accomplished in accordance with the present disclosure which comprises an air/gas dryer system having a plurality of vertical compartments formed by layering a plurality of modular units. The system has an inlet module with an air inlet port for admission of air/gas into the dryer system. Inlet air passes into a precooler/reheater module which cools the air from the inlet module while, without allowing communication between incoming and outgoing air, simultaneously warms outgoing air which is directed out of the system through an air outlet port. Precooled air then passes into an evaporator module having inlet and outlet ports for circulating refrigerant/coolant within a refrigerant flow circuit. The air is further cooled, by way of the refrigerant, until the air temperature nears 33° F. Cooling the air causes the water vapor within the air to condense into liquid water and collect in the sump module where it can then be drained out of the system. The air then passes into a filter compartment which is a dedicated vertical compartment that spans the precooler/reheater and evaporator modules. The filter compartment contains a coalescing filter which further dries the air and removes any particles. Liquid water captured by the filter is removed via a filter drain port on the evaporator module. The coalescing filter is replaceable and is accessed by an entry port on the top plate of the inlet module. The system may further comprise a dew point sensor port directly below the evaporator module and a condensation level sensor port on the Sump module. The air/gas dryer system further has a mechanical mounting means located next to the air inlet & air outlet ports and on the bottom side of the bottom plate.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure and the manner in which it may be practiced is further illustrated with reference to the accompanying drawings wherein:

FIG. 1 is a perspective view of one embodiment of a compressed air/gas dryer system of the present disclosure with the dryer system having four modules forming three chambers along a common axis.

FIG. 2 is an exploded view of the major components comprising one embodiment of the present disclosure.

FIG. 3 is an enlarged exploded view of the sump module and the bottom plate taken generally from boxed region 33 in FIG. 2.

FIG. 4 is a detailed view of one embodiment of a precooler/reheater heat exchange unit of the present disclosure.

FIG. 5 is a detailed view of an additional embodiment of a precooler/reheater heat exchange unit of the present disclosure including various baffle techniques.

FIG. 6 shows a top left perspective view of baffle assemblies utilized in one embodiment of a precooler/reheater heat exchange unit of the present disclosure.

FIG. 7 shows a side view of examples of baffle assemblies utilized in one embodiment of a precooler/reheater heat exchange unit of the present disclosure.

FIG. 8 a is a perspective view of a refrigeration evaporator heat exchange unit used in one embodiment of the present invention.

FIG. 8 b is an enlarged view of a refrigeration evaporator heat exchange unit used in one embodiment of the present disclosure taken generally from boxed region 8 b in FIG. 8 a.

FIG. 8 c is a perspective view of refrigeration evaporator heat exchange units used in one embodiment of the present invention.

FIG. 9 a is a flow schematic illustrating a representative example of the air and refrigerant flow pattern through one embodiment of a compressed air/gas drying system of the present disclosure.

FIG. 9 b is a flow schematic illustrating a representative example of the air and refrigerant flow pattern through a preferred embodiment of a compressed air/gas dryer system of the present disclosure.

FIG. 10 is an exploded view of the major components comprising a preferred embodiment of the present disclosure.

FIG. 11 a is a perspective view of a precooler/reheater heat exchange unit of the present disclosure.

FIG. 11 b is an enlarged view of a precooler/reheater heat exchange unit taken generally from boxed region 11 in FIG. 11 a.

FIG. 11 c is a perspective view of another embodiment of a precooler/reheater heat exchange unit of the present disclosure.

FIG. 12 is a detailed enlarged exploded view of a precooler/reheater heat exchange unit of the present disclosure.

FIG. 12 a is a detailed enlarged exploded view of the heat exchanger unit taken generally from boxed region 112 in FIG. 12.

FIG. 13 is a side elevational view of a preferred embodiment of a compressed air/gas drying system of the present disclosure showing the symmetrically constructed cell columns and the rod/bolt pattern of the three column cell, single row configuration.

FIG. 13A is a top view of a top plate of a preferred embodiment of a compressed air/gas drying system of the present disclosure taken generally along line 13A-13A in FIG. 13.

FIG. 13B is a top view of the inlet module of a preferred embodiment of a compressed air/gas drying system of the present disclosure taken generally along line 13B-13B in FIG. 13.

FIG. 13C is a top view of the precooler/reheater module of a preferred embodiment of a compressed air/gas drying system of the present disclosure taken generally along line 13C-13C in FIG. 13.

FIG. 13D is a top view of the evaporator module of a preferred embodiment of a compressed air/gas drying system of the present disclosure taken generally along line 13D-13D in FIG. 13.

FIG. 13E is a top view of the sump module of a preferred embodiment of a compressed air/gas drying system of the present disclosure taken generally along line 13E-13E in FIG. 13.

FIG. 14 is a perspective illustration showing the bottom plate and rod-and-bolt fasteners of an embodiment of a compressed air/gas dryer system of the present disclosure.

FIG. 15 is a perspective illustration showing the bottom plate and sump module, of a compressed air/gas dryer system of the present disclosure.

FIG. 16 a is a perspective illustration showing the bottom plate, sump module, filter, and gasket configuration for an embodiment of a compressed air/gas dryer system of the present disclosure.

FIG. 16 b is a perspective illustration showing the bottom plate, sump module, filter, and gasket configuration for an embodiment of a compressed air/gas dryer system of the present disclosure.

FIG. 17 a is a perspective illustration showing the bottom plate, sump module, filter, and gasket configuration for an embodiment of a compressed air/gas dryer system of the present disclosure.

FIG. 17 b is a perspective illustration showing the bottom plate, sump module, filter, and gasket configuration for an embodiment of a compressed air/gas dryer system of the present disclosure.

FIG. 18 a is a perspective illustration showing the bottom plate, sump module, precooler/reheater module, and refrigeration evaporator module for an embodiment of a compressed air/gas dryer system of the present disclosure.

FIG. 18 b is a perspective illustration showing the bottom plate, sump module, precooler/reheater module, and refrigeration evaporator module for an embodiment of a compressed air/gas dryer system of the present disclosure

FIG. 19 is a perspective view of an additional embodiment of a compressed air/gas dryer system of the present disclosure with the dryer system having four modules forming two chambers along a common axis.

FIG. 20 is a perspective view of one embodiment of a compressed air/gas dryer system of the present disclosure with the dryer system having four modules forming four chambers along a common axis.

FIG. 21 is a perspective view of one embodiment of a compressed air/gas dryer system of the present disclosure with the dryer system having four modules forming five chambers along a common axis.

FIG. 22 is a perspective view of one embodiment of a compressed air/gas dryer system of the present disclosure with the dryer system having four modules forming six chambers where a first row of three chambers lies parallel with a second row of three chambers.

FIG. 23 is a perspective view of the precooler/reheater and evaporator modules each welded in a single piece construction.

FIG. 24 is a perspective view of the precooler/reheater and evaporator modules as welded components.

FIG. 25 is a perspective view of the components of a further embodiment wherein the precooler/reheater exchanger and evaporator exchanger are welded in a single piece construction.

FIG. 26 is a perspective view of the precooler/reheater exchanger and evaporator exchanger as a single unit with the precooler/reheater and evaporator modules welded components.

DESCRIPTION OF SPECIFIC EMBODIMENTS

At the outset, it should be clearly understood that reference numerals are intended to identify the information found in the block diagrams in the several drawing figures, as may be further described or explained by the entire written specification of which this detailed description is an integral part. The drawings are intended to be read together with the specification and are to be construed as a portion of the entire “written description” of this disclosure as required by 35 U.S.C. §112.

Refrigerated compressed air/gas dryer systems utilize some basic components to produce clean, dry and compressed air. Typically a dryer system, will intake at the inlet wet, hot and dirty compressed air/gas which is at approximately 100 PSI and at 100° F., with a relative humidity of 100%. The precooler cools the air temperature down to about 70° F. and the evaporator further cools air temperature down to the desired dew point target of approximately 33/34° F. The air leaves the evaporator and the liquid water condensate falls out of the air and the cold dryer air/gas is filtered and further dried by the coalescing filter and enters the reheater section where it is warmed (from the incoming hot air) to about 80° F. Fahrenheit as it exits the dryer system as clean dry air, ready for use as compressed air/gas for industry. For example, a heat exchange unit is typically used to pre-cool air entering the dryer system and to reheat dry air before the air leaves the dryer. Various systems also use an evaporator for circulating refrigerant to promote condensation of water vapor followed by a means to drain-off the resultant condensation. Systems are further equipped with a filter to clean the compressed air/gas before the air/gas enters the dryer system and/or as the air/gas leaves the dryer system. Additionally, some systems utilize a filter as an intermediate stage component; such as after the evaporator and before the reheater. However, there are no dryer systems contained within a single pressurized housing that efficiently allows the passage of compressed air/gas to flow through the system and exit both dry and filtered.

The preferred embodiment of the present disclosure provides for a modularly constructed single pressurized vessel apparatus, with integral filtration, which allows a flow of both refrigerant/coolant and compressed air/gas to pass through the single structure system to achieve clean, dry and compressed air with greater economy and reduced cost of manufacturing. Increased efficiency further reduces the physical size of the pressurized system, as well as the physical size cabinetry in which the system is installed.

Adverting now to the drawings, with reference to FIG. 1 a preferred embodiment of the present disclosure of a modular compressed air/gas dryer system is indicated generally by numeral 10. Modular dryer system 10 is comprised of a modular housing. In a preferred embodiment, this modular housing is comprised of four individual horizontal modular units. The housing is comprised of inlet module 20 capped with top plate 12. Below inlet module 20 is a heat exchange precooler/reheater module 30, followed by heat exchange evaporator module 40, sump module 50, and bottom plate 14, sequentially which, when combined form a single housing creating three distinct vertical columns which direct the flow through the system. Columns 1 and 2 are passageways that direct the flow of air through the system from the inlet module to the sump module. Column 3 directs the passage of air from the sump module to the air outlet. Preferably, the housing is of an aluminum cast and/or aluminum extrusion construction. However, any suitable material can be used to form the housing including, but not limited to, another metal, an alloy, or a suitable polymeric material. Top plate 12 is equipped with filter access cap 18, while inlet module 20 is equipped with air inlet port 22, precooler/reheater module 30 has air outlet port 32, and evaporator module 40 has refrigerant/coolant inlet port 44, refrigerant/coolant outlet port 46, filter drain port 49 with a level sensor port 149 for insertion of a level sensor and a sump module 50 having a dew point port 51 for insertion of a dew point sensor. The sump drain, filter drain and liquid level sensor each afford a means to evacuate any collected condensate from the system. Bottom plate 14 is configured with threaded holes configured to accept a standard mounting means (not shown) such as threaded bolt which allows pressurized the modular dryer system 10 to be secured to a cabinet structure (not shown).

It is important to understand that each of the ports discussed above have appropriate fittings which are germane to its respective technology (such as compressed air and refrigeration technology and plumbing for the drains) that will be installed when the dryer system 10 is implemented. For example, the refrigerant/coolant ports 44 and 46 have conventional refrigeration fittings typical to that technology such as ‘flair’ fittings or ‘rotolock’ fittings because of the unique physical properties of refrigerants. Likewise in a preferred embodiment air inlet port 22 and air outlet port 32 are each configured with NPT (National Pipe Thread) pipe threads, straight thread and O-ring or a flange and gasket. Thus the ports are compatible with conventional compressed air/gas piping. In the preferred embodiment the remaining ports are fitted with conventional NPT (National Pipe Thread) or a flange with gasket. The typical connecting means to for the various inputs and outputs are constructed with a threaded type fitting (such as compressed air/gas into the system and out of the system and the port to drain the condensation out of the system to a sewer).

FIG. 2 is an exploded perspective illustration of one embodiment of a compressed air/gas dryer system of the present disclosure. In this embodiment, dryer system 10 has four modules which create three vertical columns with each module having three chambers. Inlet module 20 is capped with top plate 12. Below inlet module 20 is precooler/reheater module 30, followed by refrigeration/coolant evaporator module 40, sump module 50, and bottom plate 14, sequentially. Layered between each module is gasket 16, as well as between top plate 12 and module 20 and between bottom plate 14 and module 50. Gaskets 16 ensure pressure tight seals at the junctions between modules, and plates and modules. Gaskets such as depicted in FIG. 2 are necessary to ensure a tight leak proof modular system. Top plate 12 and bottom plate 14, along with each of the gaskets 16 between each module and plate, are preferably held together via a rod & bolt system to create a pressure tight/air tight unit. Each of the three column chambers controllably allows air to flow within each of the four modular levels. The dryer operation and air flow will be discussed in the detailed description of FIG. 9.

Top plate 12 of the compressed air/gas dryer system has a filter access hole 17 into which is removably fitted filter access cap 18. Cap 18 is equipped with an airtight seal means such as a threaded portion which mates with corresponding threads in hole 17, and/or an O-ring seal typically made out of rubber or a synthetic polymer. An airtight seal is formed when gasket 16 is sandwiched between the top plate and inlet module 20. Inlet module 20 is equipped with air inlet port 22 through which wet contaminated air is introduced to the dryer system. In this particular embodiment where three vertical columns are present, inlet module further has inlet pass-through hole 24 which allows inlet air to be split between two columns as it passes to precooler/reheater module 30.

Precooler/reheater module 30 is secured to inlet module 20 and a pressure tight seal is created by gasket 16. Precooler/reheater heat exchange units 35 are inserted into two chambers of module 30 proximate to air outlet port 32. Dried and filter air passes from the filter chamber through precooler/reheater pass-through holes 34 and exits the system through outlet port 32. Inlet air passes through precooler/reheater heat exchange units 35 and enters refrigeration evaporator module 40.

Evaporator module 40 is secured to precooler/reheater module 30 and a pressure tight seal is maintained by gasket 16. Evaporator heat exchange units 42 a and b are positioned within the two chambers of module 40 immediately below precooler/reheater heat exchange units 35 in module 30. Refrigerant/coolant enters evaporator module 40 via refrigerant inlet port 44 and flows between the two halves of evaporator heat exchange units 42 a and b through pass-through hole 48. Exchangers 42 a and 42 b have a top and bottom retainer flange 41. Vertical baffle 43 extends from the top to the bottom of the exchanger. Air directed into module 40 from module 30 travels within evaporator heat exchange units 42 a and b and passes into sump module 50.

Sump module 50 is secured to evaporator module 40 and a pressure tight seal is maintained by gasket 16. Base plate 14 is secured to sump module and a pressure tight seal is maintained by gasket 16. Sump drain port 15 in base plate 14 allows removal of any collected moisture during the air drying process. Module 40 has refrigerant/coolant inlet port 44, refrigerant/coolant outlet port 46 and filter drain port 49 with a level sensor port 149. Air leaves evaporator module 40 and passes into the sump module through the two chambers via pass-through holes 56 located directly beneath the two chambers of module 40 housing evaporator heat exchange units 42 a and b. A dew point sensor port 51 is located on sump module 50 housing directly below the first chamber of evaporator heat exchange units 42 a and b. The air then passes through pass-through holes 56 and is directed upwardly through coalescing filter seat 54. Coalescing filter 52 is seated within seat 54 using an airtight sealing means such as but not limited to a threaded connection or a threaded connection with an O-ring seal made from rubber or another suitable material such as synthetic polymer, or bayonet style connection. Coalescing filter 52 extends upwardly into evaporator module 40, precooler/reheater module 30 and inlet module 20. Liquid water (condensate) captured by the filter element (water molecules coalesce into droplets and travel down the filter) is collected within the evaporator module and is removed through evaporator drain port 49 located at the base of the filter seat. Filter 52 is removably attached to seat 54 and is accessed by removing cap 18 from top plate 12. This arrangement allows for the filter to be quickly and easily changed without necessitating the complete dismantling of the dryer system. Sump module 50 further has, a dew point port 51 for measuring and sensing the dew point value of the air/gas being dried.

FIG. 3 presents an enlarged exploded view of the sump module 50 and bottom plate 14 taken generally from boxed region 33 in FIG. 2. As shown, bottom plate 14 has a recessed edge 13 which orientates and seats gasket 16. Sump module 50 has an interlocking edge 58 located at the bottom of the module. Interlocking edge 58 interlocks with edge 13 which prevents blow-out of gasket 16 when the dryer system is pressurized, and ensures an airtight/pressure tight seal between the module and the base plate. The top of sump module 50 has recessed edge 55 for seating a gasket 16 (not shown). Gasket 16 is fully captive between each of the modules of the modular dryer system. The recessed edge/interlocking edge configuration allows each level of the dryer system to be interlocked.

FIG. 4 is an illustration of a precooler/reheater heat exchange unit 35 having a top tubesheet 36 and a bottom tubesheet 38 attached to the heat exchanger. The tubesheets seat in an airtight manner at the top and bottom of the precool/reheat chamber of module 30. Located between the tubesheets are a multiplicity of hollow parallel tubes 37. In practice heat exchanger units 35 perform two functions; a pre-cool function and a reheat function. The pre-cool function allows air flow from inlet module 20 (see FIG. 2) to pass down through the inside of tubes 37 of the tube array. The relatively cooler air from the coalescing filter chamber cools the relatively warmer inlet air passing in the tube array from the inlet module to the evaporator module.

The reheat function, allows air flow from the filter chamber to pass through pass-through holes 34 (see FIG. 2) as the air is directed to the air outlet port 32. The air is reheated by passing around and between the outside of the tubes in the array. The relatively warmer air from the inlet module passing within the tubes warms the relatively cooler air coming from the coalescing filter chamber.

FIG. 5 is an alternative precooler/reheater heat exchange unit arrangement. In this example, precooler/reheater heat exchange unit 35 retains the top tubesheet 36, bottom tubesheet 38, and multiplicity of tubes 37, with all of the mechanical characteristics thereof, of the precooler/reheater heat exchange unit arrangement illustrated in FIG. 4. However, in the embodiment of FIG. 5, baffles 39 are operatively arranged in and among tubes 37 to control the direction of airflow from the filter chamber as the air passes to the air outlet port. Baffles 39 direct the flow of air to create multiple passes, thus having multiple opportunities to transfer heat within the exchanger.

FIG. 6 shows a top left perspective view of examples of baffle assemblies utilized in one embodiment of a precooler/reheater heat exchange unit. FIG. 7 shows a side view of examples of a baffle assemblies utilized by one embodiment of a precooler/reheater heat exchange unit. Note that for clarity purposes, the tubesheets 36 and 38 and the various horizontal baffles 39 do not show the holes through which the tubes pass. As can be seen, there are two different baffle assembly arrangements, 39 a and 39 b. Using these configurations, the direction of flow comprises a ‘two-pass’ or ‘multi-path’ system. By incorporating various baffle assembly arrangements the heat exchangers can be configured to achieve optimal heat exchange performance.

FIG. 8 a is a perspective view of refrigeration evaporator heat exchange unit 42. FIG. 8 a shows the basic shape of heat exchange units 42 a and b having channels that are both vertical and horizontal. FIG. 8 b is an enlarged view of a refrigeration evaporator heat exchange unit used in one embodiment of the present disclosure taken generally from boxed region 8 b in FIG. 8 a. A vertical flow channel array 410 allows the air to pass from top to bottom through the heat exchange units 42 a and b, and horizontal flow channel array 412 allows refrigerant/coolant to pass from side to side. Vertical baffle 43 extends from the top to the bottom of the exchanger for controlling the flow of refrigerant/coolant. FIG. 8 c shows the exchange units 42 a and b assembled with a top and bottom retainer flange 41. Since refrigerant/coolant is completely surrounding the heat exchange units 42 a and b (within the chamber columns of the module 40), the baffle in this case will impede the flow outside the exchanger and force the flow through the horizontal channels 412.

The evaporator heat exchange unit functions as a refrigerant/coolant-to-air heat exchange device. The retaining flanges are disposed within the evaporator module chambers in a like manner as the precooler/reheater heat exchange unit described above and form an airtight seal such that the precooled air coming from the tube array 37 (see FIGS. 4 and 5) is directed into the evaporator heat exchange unit vertical channels 410 and does not leak around the unit. During use, refrigerant/coolant is supplied to the evaporator heat exchange unit through refrigerant inlet port 44 and circulates until it passes through exchanger 42 a and to exchanger 42 b via notch pass-through 48 in module 30 housing, to a second subunit before being recovered at refrigerant outlet port 46. The passage of expanded refrigerant at, for example 34° F., causes the compressed air/gas received from the precooler/reheater module to quickly cool down to a dew point suitable for vapors within the air/gas to condense and fall into the sump module.

FIG. 9 a is a flow schematic showing the paths of the air and refrigerant flow patterns through a preferred embodiment of the modularly constructed compressed air/gas dryer system of the present disclosure. The side cross sectional view illustrates an embodiment having four stacked modular levels 20, 30, 40, and 50 and three columns 1, 2, and 3. For the sake of clarity airflow is depicted by solid black line arrows, refrigerant flow is depicted by framed in white arrows and water exiting the system is depicted by hashed arrows.

Contaminated hot wet compressed air/gas, represented as arrow 100 enters inlet module 20 through air inlet 22. A portion of air as illustrated by arrow 100 passes through pass-through hole 24 such that contaminated air is confined to columns 1 and 2. Air then enters the tubes of precooler/reheater heat exchange units 35 (see FIG. 5) within precooler/reheater module 30 where cooling of the air progressively increases as the air moves through the exchange units in the general direction of arrows 110 and 115. The pre-cooled air flow as illustrated by arrow 120 then enters the evaporator heat exchange unit within evaporator module 40.

Refrigerant/coolant enters evaporator module 40 via refrigerant inlet port 44 (as shown in FIG. 1) and flows in the direction of arrows 180 into a first evaporator heat exchange unit and flows into a second evaporator heat exchange unit through pass-through hole 48. All refrigerant is circulated and distributed throughout evaporator module 40 and enters cavities 146 & 148 from refrigerant that flows in the general direction of arrows 183 and 185. Refrigerant accumulates on the leading side of the evaporator heat exchanger in cavity 146 and after it moves through the heat exchanger it is collected on the after side of the evaporator heat exchanger in cavity 148. A similar process occurs for the air flow precooler/reheater module 30 as air fills cavities 136 & 138. The cavities allow for even distribution of airflow and refrigerant.

Refrigerant quickly cools the air which flows in the direction of arrows 120 and 125 and causes vapor to condense and drip into sump module 50. Collected water 191 drains from the system through sump drain port 15 in the general direction of arrow 190. Removal of condensate is one of the objectives of the dryer system. When air leaves module 40 it is cooled and dried air traveling in the direction of arrow 130 and the air passes through pass-through holes 56 and enters column 3 in the general direction of arrow 131.

Column 3 has coalescing filter 52 seated at the top of sump module and extending upwardly through evaporator module 40 and partway into precooler/reheater module 30. Cooled dry air passes into coalescing filter 52 in the general direction of arrows 140 thereby removing particles in the air while any remaining moisture coalesces into droplets that fall down the outer surface of filter 52 and collect at the bottom of column 3 of the evaporator module. Liquid condensate 196 is then removed through filter chamber drain port 49 in the general direction of arrow 195. The cleaned, dry cold air then passes in the general direction of arrow 145 into precooler/reheater column 2 through first pass-through hole 34.

Relatively cooler air leaves evaporator module 40 and enters precooler/reheater module 30 in the general direction of arrow 145 and passes through a first precooler/reheater heat exchanger in the general direction of arrow 150. Cooler air coming from the coalescing filter chamber is gradually warmed as it moves in the general direction of arrow 155. Air then passes in the general direction of arrow 155 through a second pass-through hole 34 into a second precooler/reheater heat exchange subunit. The air flow from the second precooler/reheater heat exchange subunit is directed to the air outlet port 32. The air is reheated by passing around and between the outside of the tubes in the precooler/reheater heat exchangers. The tubes in the heat exchangers contain air flowing in the general direction of arrow 110 entering the system on the precooler side of the exchanger. The heat exchange occurs when the relatively warmer air from the inlet module passing within the tubes warms the relatively cooler air coming from the coalescing filter chamber; and the relatively cooler air coming from the coalescing filter chamber cools the relatively warmer air coming from the inlet module. The air flowing in the general direction of arrow 160 merges in cavity 138 before exiting dryer system as air flowing in the general direction of arrow 170 through outlet port 32.

In another preferred embodiment of the present disclosure having a baffle configuration assembly such as depicted in FIGS. 6 and 7, the baffle configuration causes the air to take multiple paths around the baffles and tubes causing the air to become warmer and exit the system in the general direction of arrow 165. The clean, dry, filtrated, warmed compressed air then exits the system through air outlet port 32 in the general direction of arrow 170.

FIG. 9 b is a flow schematic showing the paths of air and refrigerant flow patterns through a another preferred embodiment of the modularly constructed compressed air/gas dryer system of the present disclosure. This preferred embodiment of the modularly constructed compressed air/gas dryer system is utilizing a single precooler/reheater heat exchange unit 300 (as shown in FIG. 10) and an evaporator heat exchanger 400 (as shown in FIG. 10) as opposed to a pair of precooler/reheater heat exchange units 35 and evaporator exchange units 42 a and b utilized in the preferred embodiment of the present disclosure illustrated in FIG. 2.

Hot and wet compressed air/gas flowing in the direction of arrow 100 enters inlet port 22, passes through the precooler generally in the direction of arrows 110 and 115, and continues through the evaporator in the general direction of arrows 120 and 125 where it exits into the sump in the general direction of arrow 130. The moisture in the air turns to liquid water 191 (condensate) and exits the system in the general direction of arrow 190 through sump drain port 15. The cold dry air flowing in the general direction of arrow 131 continues up into column 3 and passes through coalescing filter which collects and filters-out particulates in the air. The large liquid condensate in air flowing in the direction of arrow 130 is drained-off and out sump drain port 15. As the air flow continues into the filter chamber and pass through the filter, any remaining smaller water molecules will coalesce and trickle-down to outer surface of the filter and collect at the base. A liquid level sensor (when installed into sensor port 149, see FIG. 1) detects a specified level, this would allow the dryer system to activate the drains (electrical drain solenoids are not shown) and evacuate any collected condensate.

Remaining water molecules coalesce and are drained out port 49 as condensate in the general direction of arrow 195. The cleaned, dried filtered air generally traveling in the direction of arrow 145 exits column 3 and passes through pass-through 34 into air distribution cavity 136 of precooler/reheater module 306. Distribution cavity 136 serves to equally deliver air to the approach side of the reheater section of the precooler/reheater in the general direction of arrow 150. The air leaves the reheater in the general direction of arrow 160 and enters air after cavity 138 where it exits through outlet port 32 as dry clean filter air in the general direction of arrow 170. Refrigerant/coolant circuit (in evaporator module 406) receives refrigerant/coolant from refrigerant inlet port 44 (see FIG. 1). The circuit has a refrigerant distribution cavity 146 on the approach to the evaporator heat exchanger, and a refrigerant after cavity 148 to collect refrigerant/coolant before exiting the evaporator module via port 46.

FIG. 10 is an exploded view of an additional preferred embodiment of modular compressed air/gas dryer system 500 of the present disclosure. The embodiment illustrated in FIG. 10 is identical to the embodiment illustrated in FIG. 2 except for a few modifications. Precooler/reheater module is operatively arranged such that a single precooler/reheater heat exchange unit 300 can be inserted within the module. This single unit design has top retainer flange 360 and bottom retainer flange 380 which fit in an air tight manner within precooler/reheater module 306. Modified gaskets 19 are configured to accommodate a single pre-cooler/reheater heat exchange unit and a single evaporator heat exchanger to ensure pressure tight seals at the junctions between modules, and plates and modules. Gaskets such as depicted in FIG. 10 are necessary to ensure a tight leak proof modular system. An array of vertical channels 370 and horizontal channels 375 are interleafed to one another to create airflow channels to make up the heat exchange unit.

Evaporator heat exchanger 400 has top flange 460 and bottom flange 480. An array of vertical channels 470 and horizontal channels 475 are interleafed allowing the exchange of heat from air flowing through the vertical channels and refrigerant flowing through the horizontal channels. Evaporator module 406 is operatively arranged with a cavity to house a single evaporator heat exchanger 400.

FIG. 11 a is a perspective view of a precooler/reheater heat exchange unit of the present disclosure. Heat exchanger 300 is sandwiched between outer plate 314 and corner support 316. FIG. 11 b is an enlarged view of a precooler/reheater heat exchange unit taken generally from boxed region 11 in FIG. 11 a. FIG. 11 b shows an enlarged view of vertical channels 370 and horizontal channels 375. The channels are formed from corrugated sheets of aluminum that are oriented within the heat exchanger to have layers of vertical channels 370 and horizontal channels 375 which are positioned on opposite sides of an isolation barrier sheet 318 which is a flat sheet of aluminum interleafed between each vertical and horizontal channeled sheet. The sheets have a horizontal straight edge 372 and a vertical straight edge 376 opposite its respective corrugated pattern 371 (as shown in FIG. 12).

FIG. 11 c is a perspective view of another embodiment of a precooler/reheater heat exchange unit of the present disclosure. FIG. 11 c shows top retainer flange 360 and bottom retainer flange 380 affixed as if it were inserted into module 306. It is to be expressly understood that the vertical and horizontal channels are completely isolated from one another when the exchanger 300 is installed into the assembly according to the teaching of the present disclosure.

FIG. 12 is an exploded view of heat exchanger 300 showing the construction and direction of channels of the inner sheets. Heat exchanger 300 is made up of an assembly of aluminum sheets having channels which are positioned to allow air to flow both vertically and horizontally through the heat exchanger. The sheets are oriented within the heat exchanger to have layers of vertical channels 370 and horizontal channels 375 which are positioned on opposite sides of an isolation barrier sheet 318 which is a flat sheet of aluminum interleafed between each vertical and horizontal channeled sheet.

FIG. 12 a is a detailed enlarged exploded view of the heat exchanger unit taken generally from boxed region 112 in FIG. 12. Vertical channels 370 and horizontal channels 375 are formed conventionally by sheets of aluminum which are pressed in a press and die to result in a corrugation pattern 371. The corrugated form makes the channels which help transfer heat between the channel layer and the isolation barrier 318 by isolating and directing air flow. The outer panels 314 encase and seal the assembly of aluminum sheets as the layers of vertical and horizontal corrugated forms and isolation barrier sheets are retained by corner support 316 and notch 320 in corner support 316 receives the corner edges of the vertical channels 370, horizontal channels 375 and isolation barriers 318. The entire assembly is conventionally fused together by any number of processes, for example dipped and brazed, soldered, sonic weld, ultrasonic weld, microwave bonding fusion bonding, etc. The preferred method of sealing/fusing the present disclosure is a braze bonding process using an appropriate alloy to fuse an approximate 0.0156 inch thick aluminum material for the channeled aluminum sheets, and a 0.03125 inch thick aluminum material for the flat isolation barriers. In like manner, outer panels 314 are made of an approximate 0.125 inch thick (or thicker) aluminum material which are—braze bonded to the inner channels and barriers with the corner supports 316. The resulting structure can withstand several hundred degrees of temperature and several thousand pounds per square inch shear pressure. Further, all heat exchangers described in this disclosure are preferably bonded via brazing methods. It is important to understand that the corrugated aluminum heat exchanger described herein is most suitable in a compressed air/gas environment. In the preferred embodiment of the present disclosure the two sides of the exchanger are configured to withstand the pressures and temperatures typically found in such environments.

In operation, inlet air enters module 306 through inlet module 20 through air inlet and passes to evaporator module 406 by going within the vertical channels 370. Air leaving the system through air outlet port 32 is directed by horizontal channels 375 without contact or mixing with the inlet air. Similarly, evaporator module 406 is designed to fit a single evaporator heat exchange unit 400 within the module as shown in FIG. 10. The construction of an evaporator heat exchanger 400 is identical to the precooler/reheater heat exchanger 300 presented above except it is installed into an evaporator module 406 housing. Heat exchanger 400 is comprised of vertical channel array 470 and horizontal channel array 475, top retaining flange 460, and bottom retaining flange 480 as shown in FIG. 10. Heat exchanger 400 is installed in module 406 in like manner as exchanger 300 is installed into module 306 housing, with both being completely air pressure tight.

Air entering evaporator module 406 from precooler/reheater module 306 passes through the evaporator heat exchange unit 400 where the air is rapidly cooled to about 34° F. thereby causing moisture within the air to condense and fall into sump module 50. The air is rapidly cooled by action of a refrigerant circulating within evaporator heat exchange unit 400. Refrigerant is supplied via refrigerant inlet port 44 and removed through refrigerant outlet port 46 as was discussed previously. In all other respects, additional preferred embodiment of modular compressed air/gas dryer system 500 of the present disclosure is constructed and operates in the manner described above with reference to the dryer system 10 (See FIGS. 1 and 2).

FIG. 13 is a side elevational view of a preferred embodiment of a compressed air/gas drying system of the present disclosure showing the symmetrically constructed cell columns and the rod/bolt pattern of the three column cell, single row configuration. FIG. 13A is a top view of a top plate of a preferred embodiment of a compressed air/gas drying system of the present disclosure taken generally along line 13A-13A in FIG. 13.

FIG. 13B is a top view of the inlet module of a preferred embodiment of a compressed air/gas drying system of the present disclosure taken generally along line 13B-13B in FIG. 13. The top views 13A through 13E show the openings of each module. FIG. 13C is a top view of the precooler/reheater module of a preferred embodiment of a compressed air/gas drying system of the present disclosure taken generally along line 13C-13C in FIG. 13. FIG. 13D is a top view of the evaporator module of a preferred embodiment of a compressed air/gas drying system of the present disclosure taken generally along line 13D-13D in FIG. 13. FIG. 13E is a top view of the sump module of a preferred embodiment of a compressed air/gas drying system of the present disclosure taken generally along line 13E-13E in FIG. 13.

FIGS. 14 through 18 are perspective illustrations showing each skeletal level of the present disclosure, starting from the bottom plate and gradually building a complete system including the various levels in its modular construction. FIG. 14 is a perspective illustration showing the bottom plate and rod-and-bolt fasteners of a compressed air/gas drying system of the present disclosure showing the symmetrically constructed cell columns outlined by a multiplicity of rod/bolts 8 mounted to bottom plate 14. As can be readily observed in FIG. 14, three sets of four rod/bolts 8 create the skeleton of a three column cell. In operation, modular construction affords serviceability of each independent module, filter, gasket and heat exchanger. The removability of the rods and bolts allows for easy disassembly and reassembly of the dryer modular unit. During the lifetime of the modular dryer, cleaning and repair is easily accomplished because every part of the modular unit is replaceable.

FIG. 15 is a perspective illustration showing the bottom plate and sump module 50 of a compressed air/gas dryer system of the present disclosure. Sump module 50 is configured so that its three circular cavities can accommodate any combination of heat exchanger design, such as a single precooler/reheater heat exchange unit 300 and a single evaporator heat exchanger 400 (as shown in FIG. 10) or two precooler/reheater heat exchange units 35 and two evaporator heat exchange units 42 a and b (as shown in FIG. 2), to achieve the desired dryer function. It should be understood to one skilled in the art that the dryer system of the present disclosure can utilize any combination of heat exchanger. Again, it is important to understand that this flexibility can support a number of system functions and capabilities.

FIG. 16 a is a perspective illustration showing the bottom plate, sump module, filter, and gasket configured to accommodate an embodiment of a compressed air/gas dryer system of the present disclosure having two precooler/reheater heat exchange units 35 and two evaporator heat exchange units 42 a and b (as shown in FIG. 2)

FIG. 16 b is a perspective illustration of another embodiment of a compressed air/gas dryer system of the present disclosure showing a multiplicity of rod/bolts 8 mounted to bottom plate 14, sump module 50 having coalescing filter 52, and modified gasket 19 configured to accommodate a single precooler/reheater heat exchange unit 300 and a single evaporator heat exchanger 400 (as shown in FIG. 10). It should understood that although this sequence of parts is one example of how to build a compressed air/gas drying system of the present disclosure it should be obvious to one skilled in the art of mechanical assembly that such interlocking modules would have gaskets appropriately layered to achieve a fully assembled, air-tight final configuration.

FIG. 17 a is a perspective illustration of an embodiment of a compressed air/gas dryer system of the present disclosure having a multiplicity of rod/bolts 8 mounted to bottom plate 14, sump module 50 having coalescing filter 52, gasket 16 and two precooler/reheater heat exchange units 35 and two evaporator heat exchange units 42 a and b attached thereto.

FIG. 17 b is a perspective illustration of another embodiment of a compressed air/gas dryer system of the present disclosure showing a multiplicity of rod/bolts 8 mounted to bottom plate 14, sump module 50 having coalescing filter 52, modified gasket 19 and a single precooler/reheater heat exchange unit 300 and a single evaporator heat exchanger 400 attached thereto.

FIG. 18 a is a perspective illustration showing the bottom plate, sump module 50, precooler/reheater module 30, and refrigeration heat exchange evaporator module 40 for an embodiment of a compressed air/gas dryer system of the present disclosure configured to accommodate two precooler/reheater heat exchange units 35 and two evaporator heat exchange units 42 a and b (as shown in FIG. 2)

FIG. 18 b is a perspective illustration of the bottom plate, sump module, precooler/reheater module, and refrigeration evaporator module for an embodiment of a compressed air/gas dryer system of the present disclosure configured to accommodate a single precooler/reheater heat exchange unit 300 and a single evaporator heat exchanger 400 (as shown in FIG. 10). It should be understood that any of the dryer systems disclosed above, can be disassembled for repair, cleaning or replacement of subcomponents (by removing the rod and bolts) during the life of the system.

FIG. 19 is another alternative embodiment of the present disclosure comprised of a two cell column arrangement having four modular levels. Note that one of the cell columns is a chamber configured to accommodate a coalescing filter and the other cell column is a chamber configured to accommodate a single precooler/reheater heat exchange unit 35 and a single evaporator heat exchange unit 42 a (as shown in FIG. 2).

FIG. 20 shows another embodiment of a compressed air/gas dryer system of the present disclosure showing comprising a four cell columns configuration with four modular levels. In this case, the dryer system is configured to accommodate two levels of replaceable filters. As can be appreciated, the current disclosure is made to accommodate various sized and shaped types of filters. The various column configurations are for illustrative purposes only and are not meant to be limiting. In addition, the filters used in the system of this disclosure are made from various ‘grades’ of refinement such as microns of filtration or different combinations of the same, for example. The type of filter used to construct the dryer system is dependent on circumstance, for instance the two filters can be different ‘types’ of filtration such as a particulate/coalescing pre-filter and a coalescing intermediate stage filter. In a further alternative, the dryer system of the instant disclosure can use an intermediate coalescing filter with an after-filter arrangement.

FIG. 21 is another embodiment of the present disclosure wherein the dryer system has five cell columns in a single row and four modular levels. This alternate embodiment of a compressed air/gas dryer system of the present disclosure is configured to accommodate three different filtration means, e.g., particulate/coalescing pre-filter, coalescing intermediate stage filtration, and an after-filter.

FIG. 22 is another alternative embodiment of the present disclosure where the dryer system has a two row configuration made up of four modular levels. In this alternative embodiment, the compressed air/gas dryer system is configured to accommodate a ‘doubled’ capacity by having more cell columns, with more precooler/reheater heat exchanger elements, more evaporator heat exchanger elements and more intermediate coalescing filter elements than the compressed air/gas dryer system accommodating a single and a double heat exchange module.

FIG. 23 is an exploded view of another preferred embodiment of the precooler/reheater and evaporator modules each welded in a single piece construction. In this embodiment of the present disclosure precooler/reheater heat exchanger 300 is welded to chamber housing 392 and outlet frame 394. Once air outlet frame 394 is attached to exchanger 300 it creates an after cavity 138. Each individual element welded together results in a single piece construction. This embodiment differs from a preferred embodiment in that it eliminates the necessity of inserting the heat exchanger into a module such as precooler/reheater module 306 as shown in FIG. 10. Top member 390 and bottom member 395 are welded to precooler/reheater heat exchanger 300. In this embodiment precooler/reheater heat chamber housing 392 is directly welded to exchanger 300. Both precooler/reheater heat chamber housing 392 and air outlet frame 394 are configured to have a distribution cavity 136 and after cavity 138 respectively. Although the structures differ in the modular construction as shown in FIGS. 2 and 10 the structures function alike.

In addition, this embodiment differs from a preferred embodiment in that it eliminates the necessity of inserting the heat exchanger into a module such as heat exchange evaporator module 406 as shown in FIG. 10. In like manner, evaporator heat exchanger 400 is configured with top member 490, bottom member 495, evaporator chamber housing 492, refrigerant outlet frame 494, all welded together in a singular construction resulting a heat exchanger which functions the same as a heat exchanger would contained within evaporator module 406.

FIG. 24 is a perspective view of precooler/reheater 307 and evaporator 407 shown assembled in a single piece construction from their component parts as depicted in the exploded view of FIG. 23. Precooler/reheater module 307 and evaporator module 407 are each a single piece construction module having the same function of precooler/reheater module 306 and evaporator module 406 with their constituent heat exchangers inserted in their respective cavities as described herein and illustrated in FIG. 10. This welded singular construction is advantageous for reducing fabrication cost but does not have the advantages of easy replacement parts of that of replaceable modular system described herein.

FIG. 25 is an exploded view of an additional preferred embodiment of modular compressed air/gas dryer system 607 of the present disclosure wherein the precooler/reheater exchanger and evaporator exchanger are welded in a single piece construction 600.

FIG. 26 is a perspective view of an additional preferred embodiment of modular compressed air/gas dryer system 607 of the present disclosure wherein precooler/reheater exchanger and evaporator exchanger are constructed as a single construction. Modular compressed air/gas dryer system 607 comprises outer panel 314 extending the full height of both exchangers, giving the unit a seal that is air and pressure tight, and completely isolating the heat exchangers from one another. Top member 390 and bottom member 495 are mounted to the heat exchangers, which facilitate the mounting of precooler/reheater heat chamber housing 392 and evaporator chamber housing 492; and refrigerant outlet frame 494 and air outlet frame 394. Once these components are fixedly mounted to each other by welding or other like method, they form a single constructed unit having the same function of the modules 306 and 406 as described herein and illustrated in FIG. 10. It should be understood that in order to ensure a complete pressure tight seal of the evaporator section contained in the compressed air/gas dryer system 600, the manufacturing evaporator components chamber housing 492 and refrigerant outlet frame 494 are welded to the heat exchanger before components precooler/reheater heat chamber housing 392 and air outlet frame 394. In this manner mechanical welding can be on all four surfaces around cavities 146 and 148. It should be further noted that the precooler/reheater heat chamber housing 392 and air outlet frame 394 can only be welded to the heat exchanger on the top and side surfaces around cavities 136 and 138. However a pressure tight weld 496 and 498 is will ensure the unit is completely air tight. A minor passage of clean dried air from the filter chamber into distribution cavity 136 instead of passing through pass-through 34 is relatively inconsequential.

Although the disclosure has been described in several embodiments and configurations, with reference to certain preferred embodiments, it will be appreciated by those skilled in the art that modifications and variations may be made without departing from the spirit and scope of the disclosure. It should be noted that the above preferred embodiment depicts typically a 1000 standard cubic feet per minute (scfm) dryer system capacity. To achieve a smaller or larger capacity dryer system (for example 500 scfm or 1200 scfm), a simple change in the inlet port 22 and outlet port 32 sizing would make such dryer system modifications. Still further, again by example, a smaller or larger capacity can be achieved by altering the ‘height’ of precooler/reheater module 30 and evaporator module 40. The height change would either extend or shorten the contact time the air or refrigerant is making to various surfaces within the heat exchangers, thus modifying the capacity to suit any desired scfm. And it is obvious that using any of the considerations shown in FIGS. 19 through 22 can dramatically change desired scfm capacity and functionality configurations by simply adding (or subtracting) column chambers. It should be understood that applicant does not intend to be limited to the particular details described above. 

1) A modular compressed-gas dryer system comprising: a flow through gas system, including in series, a) an inlet module for introducing incoming gas into said system; b) a precooler/reheater module for housing a gas-to-gas heat exchanger; c) an evaporator module for housing a refrigerant-to-gas heat exchanger; d) a sump module for collecting and draining condensate from said system; e) wherein said modules together form a plurality of columns for creating gas flow through passages where at least one of said columns has a filtration chamber for housing a filter; f) a gas outlet for discharging outgoing gas; g) a sealing means interposed between respective modules to ensure a gastight seal; h) a first set of heat transfer passages extending through said heat exchangers in which said incoming gas passes serially through said heat exchangers in a first direction; i) a second set of heat transfer passages extending through said evaporator module in heat exchange relationship with said first set of heat transfer passages through which a charge of refrigerant passes in a heat exchange relationship with said incoming gas and in a direction substantially perpendicular to said first direction of said incoming gas to produce chilled gas; j) a filtration passage within said filtration chamber for conducting said chilled gas through said filter from said first set of heat transfer passages to a third set of heat transfer passages; k) said third set of heat transfer passages extending through said precooler/reheater module in heat exchange relationship with said first set of heat transfer passages and through which chilled gas passes in heat exchange relationship with said incoming gas and in a direction substantially perpendicular to said first direction of said incoming gas; and l) so that said incoming gas is chilled in said evaporator module and chilled gas therefrom exchanges heat with said incoming gas in said precooler/reheater module to precool said incoming gas and to raise the temperature of said chilled gas to a temperature for ultimate use upon discharge. 2) The modular compressed-gas dryer system of claim 1 wherein said series of modules are removably held together by a multiplicity of rods and bolts and wherein said sealing means is a gasket and mating interlocking edges between each module. 3) The modular compressed-gas dryer system of claim 1 wherein said filtration chamber houses a replaceable filter. 4) The modular compressed-gas dryer system of claim 3 wherein said filter is a coalescing filter. 5) The modular compressed-gas dryer system of claim 1 wherein said gas-to-gas heat exchanger is a tube-and-shell heat exchanger. 6) The modular compressed-gas dryer system of claim 5 wherein said tube-and-shell heat exchanger is equipped with a baffle assembly. 7) The modular compressed-gas dryer system of claim 1 wherein said heat exchangers are constructed as corrugated sheet units having vertical channels and horizontal channels. 8) The modular compressed-gas dryer system of claim 1 further comprising a sensor port for insertion of a level sensor and a dew point port for insertion of a dew point sensor. 9) A modular compressed-gas dryer system comprising: a flow through gas system, including in series, a) an inlet module for introducing incoming gas into said system; b) at least one precooler/reheater module for housing a gas-to-gas heat exchanger; c) at least one evaporator module for housing a refrigerant-to-gas heat exchanger; d) a sump module for collecting and draining condensate from said system; e) wherein said modules together form a plurality of columns for creating gas flow through passages where at least two of said columns have a filtration chamber for housing a filter; f) a gas outlet for discharging outgoing gas; g) a sealing means interposed between respective modules to ensure a gastight seal; h) a first set of heat transfer passages extending through said heat exchangers in which said incoming gas passes serially through said heat exchangers in a first direction; i) a second set of heat transfer passages extending through said evaporator module in heat exchange relationship with said first set of heat transfer passages through which a charge of refrigerant passes in a heat exchange relationship with said incoming gas and in a direction substantially perpendicular to said first direction of said incoming gas to produce chilled gas; j) a third set of heat transfer passages extending through said precooler/reheater module in heat exchange relationship with said first set of heat transfer passages and through which chilled gas passes in heat exchange relationship with said incoming gas and in a direction substantially perpendicular to said first direction of said incoming gas; k) at least one filtration passage within said at least two of said columns having a filtration chamber for conducting said gas from any one of said modules to one of said heat transfer passages; and l) so that said incoming gas is chilled in said evaporator module and chilled gas therefrom exchanges heat with said incoming gas in said precooler/reheater module to precool said incoming gas and to raise the temperature of said chilled gas to a temperature for ultimate use upon discharge. 10) The modular compressed-gas dryer system of claim 9 wherein said series of modules are removably held together by a multiplicity of rods and bolts and wherein said sealing means is a gasket and mating interlocking edges between each module. 11) The modular compressed-gas dryer system of claim 9 wherein said gas-to-gas heat exchanger is constructed as a tube-and-shell heat exchanger. 12) The modular compressed-gas dryer system of claim 11 wherein said tube-and-shell heat exchanger is equipped with a baffle assembly. 13) The modular compressed-gas dryer system of claim 9 wherein said heat exchangers are constructed as corrugated sheet units having vertical channels and horizontal channels for directing gas and refrigerant. 14) The modular compressed-gas dryer system of claim 9 wherein each of said at least two of said columns having a filtration chamber houses a replaceable filter. 15) The modular compressed-gas dryer system of claim 14 wherein one said at least two of said columns having a filtration chamber houses a replaceable filter and conducts said gas from said inlet module to a first of said at least one precooler/reheater modules. 16) The modular compressed-gas dryer system of claim 15 wherein one said replaceable filter is a particulate/coalescing filter. 17) The modular compressed-gas dryer system of claim 14 wherein one said at least two of said columns having a filtration chamber houses a replaceable filter and conducts said gas from said sump module to said at least one precooler/reheater module. 18) The modular compressed-gas dryer system of claim 17 wherein one said replaceable filter is a coalescing filter. 19) The modular compressed-gas dryer system of claim 9 wherein said at least one precooler/reheater module for housing a gas-to-gas heat exchanger is two precooler/reheater modules for housing two gas-to-gas heat exchangers; and wherein said at least one evaporator module for housing a refrigerant-to-gas heat exchanger is two evaporator modules for housing two refrigerant-to-gas heat exchangers; and wherein said at least two of said columns have a filtration chamber for housing a filter is two filtration chambers each housing a filter. 20) The modular compressed-gas dryer system of claim 9 further comprising a sensor port for insertion of a level sensor and a dew point port for insertion of a dew point sensor. 